1. Field of the Invention
The present invention relates to detection patterns for detecting displacement of a probe in operation attached to a semiconductor device having a plurality of IC chips formed on a silicon substrate and formed of semiconductor elements, such as a transistor, and a pad region for probing.
2. Description of the Related Art
Conventionally, a probing test is generally carried out for an ordinary IC to check electrical characteristics after manufacturing.
Further, minimizing intervals between pads used in a probing test enables chip size reduction in an IC having many pads, and is indispensable to reduce IC cost.
Though the probing test is often carried out with thin detection needles, effect of displacement of the needle is larger in an IC having many pads for probing since the pad interval is small.
It is an important theme in a probing process to detect displacement of the probing needle in advance in order to prevent possible errors. For example, JP 06-45419 A discloses a technique in which pads for detecting displacement of needles in probing are provided while carrying out measurement.
As described in the above, however, effect of displacement of the needle is larger in an IC having many pads for probing since the pad interval is small, resulting in the problems of inaccurate probing test, and capture of erroneous characteristics, and the like. In order to solve these problems, for example, a technique has been disclosed where a plurality of special pads for detecting displacement of a needle in operation are provided while carrying out measurement. However, such technique has problems of the large occupation area for pads, inability in detecting the direction of the displacement, and the like.